| 摘要 |
A method and a welding unit for producing a seam-welded tin roof made of roofing sheets (30) with large flange (31) and low flange (32), the low flange on a sheet (30) placed on the underlay (50) being secured to the load-bearing structure of the roof by means of a bracket (40) comprising a base plate secured to the load-bearing roof structure, and a tongue protruding upwardly from the roof underlay, said tongue being connected to the low flange (32), and the large flange (31) on the following roofing sheet (30) being joined above the low flange of the previous sheet (30), and the join between low flange and large flange being seam-welded (55) along its length. A bracket (40) is used, the tongue of which has an end portion (41) which is bent out approximately 90° so as to lie parallel, close to and above the end portion (34) of the low flange (32), the end portion lying parallel with the main surface of the roofing sheet (30). The join between large flange and low flange is folded at its upper portion for connection of the bracket (40) to the roofing sheets (30). The seam-welding (55) is performed after the folding, using a welding unit (61, 62, 72) resting on the flange (39) and being displaced along said flange, the welding unit being provided with welding jaws (61, 62) applied to opposing sides of the upwardly protruding waist section of the flange-joint, spaced above the main surface of the roofing sheets (30). |
